One hundred-slxty eight. 24·weeks old. Bovans Brown commercial egg-type
laying hens were randomly and equally divided into saver- qroups (8 replicates per
group. each of 3 birds). These groups were randomly assigned on 7 experimerual
diels including a typical cern-soybean control diet and diets either containing 5. 10 or
15% dried algae (Scenedesmus acurus): or containing 5. 10 or 15% dried Azolla.
Each of algae and Azolla were used as a partial substitution for soybean meal of the
control diet on an isonitrogenous basis. Hens were fed the experimental diets for 12-
weeks test period. Either dietary algae up to 10% or 5% dietary Azou« did not affect OM or CP
digestibility, but only at the higher Ievets. digestibility was decreased. Non of dietary
treatments affect EE. CF or NFE digestibility. excepting a decrease in EE digestibility
observed With the 15 % dielaf'j Azolia, and decreases in both CF and NFE digestibility
with the 10 and 15% dietary Azolla; in addition to enhancement of NFE digestibility
due \0 5 and 10% dietary algae. Egg production and egg weight were not affected by 5% algae or Azalia in
hen diets. However signiijcant decreases in both parameters were observed on the
higher levels. Feed intake was significantly reduced wilh 10 and 15% dietary Azol/a
Up to TO% dietary algae or 5% dietary Alolla did not affect feed conversion. but
negative effectes were observed at me higher stud'led levels. Non of dietary algae or Azalia affect both internal and external egg quality
parameters. however. s'lgniricant decreases in haugh unit and albumen% were
observed 011 the 15% Azalia and 5% algae levels, resoectiveiy. fI.It te'Jets of dielary
algal rnesl tended to enhance yolk color, but only at the 15% level. Azol/a Significantly
enhanced yolk color, compared to the control. All the tested diets increased plasma total protein. albumin. and globulin
values, except for 5% Azolla diel. Significant decrease was observed in total lipids on
the T 5% dietary Azolla. with significant elevations in cholesterol level occured at the
10 and 15% levels Both algae and Azolla elevated plasma uric acid. These data suggest that either dried algae or Azolla at 5% dietary le\let are
useful as partiat alternatives to soybean meal in raying hen diets on an isonitrogenous
basis. for maintaining egg production and qU3tity, but even this level of algae tend to
enhance yolk color score.